This charts shows the result of recent survey (asked to Americans) conducted by Gallup poll about gender preferences: Suppose you could only have one child. Would you prefer that it be a boy or a girl?

The attitudes of American men drive the overall preference for a boy; in the current poll, conducted June 9-12, men favor a boy over a girl by a 49% to 22% margin. American women do not have a proportionate preference for girls. Instead, women show essentially no preference either way: 31% say they would prefer a boy and 33% would prefer a girl. (Gallup poll)